Tactile displays provide a means to utilize the sense of touch as a mode of communication. Technology development for tactile displays is driven by a number of applications. In teleoperation scenarios, including robotic surgery and bomb disposal, a tactile display at the master side can help restore some of the haptic feedback that the user loses by not interacting directly with the environment on the slave side. For individuals with auditory or visual impairments, a tactile display can serve as a form of sensory substitution to physically convey some of the information normally perceived by the impaired sense. Additionally, a tactile display can increase the realism of a virtual reality by immersing more senses of the user with the interface. In medical simulation, a compelling tactile display can play a vital role in ensuring effective training. Haptics play an important role in a clinician's diagnoses and decision regarding many procedures. Palpation is often necessary to identify subcutaneous anatomical landmarks or to differentiate between similarly shaped objects. By including a tactile display, virtual reality-based simulation can help clinicians gain experience tuning their sense of touch prior to performing a procedure or diagnosis on an actual patient.
While the technologies to convey visual and auditory information, such as LCD screens and surround speakers, have advanced to provide almost indistinguishable replication of sights and sounds, the technologies to mimic haptic sensations lag relatively far behind. The challenges inherent in synthesizing compelling recreations of physical interactions might provide a likely explanation for the gap in sensory display technologies. High-quality haptic feedback requires not only accurate kinesthetic feedback and lower-frequency forces, but also realistic cutaneous feedback of finger pad contact area, textures, and high-frequency vibrations. Encountered-type tactile displays can aim to recreate realistic haptic sensations by producing physical environments for a user to explore directly with his or her hands. Unlike sight and hearing, touch is bidirectional in that the haptic sensations delivered by an environment depend not only on its physical state, but also on the manner of the user's interactions. A tactile display that more accurately mimics the shape of an environment does not suffice to realistically recreate the feel of that environment; it must also deform and respond accordingly to the user's applied forces and motions. The present invention advances the art of sensory display technology by providing sense of rigidity and local shape in a display.